The invention pertains to telephony and, more particularly, to systems and processes for call and call feature setup, administration and processing on public switched telephone networks (PSTN) and other telecommunications networks.
Voice telephony (and data communication via telephone modem) today is conducted primarily by “copper loops” or wireless transmission (via base station) from the user or subscriber to a central office (Class 4/5) switch that initiates the process of connecting the call to its ultimate destination, whether in the same local exchange handled by the central office, or to a remote central office. The call set-up process involves a series of “trigger points” wherein the service options available to the caller are checked against a database that periodically downloaded to the switch from the local carrier's database (typically relational, i.e., table-based). At the central office switch of the receiving subscriber, a similar sequence is followed to check such service options as call waiting and call forwarding. Updates of the databases are cumbersome, and adding new services require additional programming and trigger points in an already complex code.
The process of call set up outside the local service area further requires an “out of band” communication over the SS7 (“Signaling System 7”) network and protocols distinct from the network over which voice traffic flows. It is this system that allows the proper switching of traffic for roaming cellular subscribers and for 800- and 900-numbers. It also provides caller identification. The system, however, is limited in its bandwidth and by the small number of knowledgeable programmers.
The prior art has made advances in the middle or “control” layer of a three-layer network model for voice telephony as part of a trend towards “Advanced Intelligent Networks” (“AIN”). These advances have involved call agents using the SS7 network to control new functionality in call set up and upgrading of the International Telecommunications Union H.323 Internet protocol for coordination of voice, data, and video traffic on the Public Switched Telephone Network (PSTN). For example, Bellcore and Cisco developed the Simple Gateway Control Protocol (SGCP) to improve on H.323 and Level 3 developed the Internet Protocol Device Control (IPDC). The Media Gateway Control Protocol (MGCP) is a merger of SGCP and IPDC sponsored by the Internet Engineering Task Force to migrate SS7 functions into Internet Protocol (IP).
The current state of the art remains one of limited service options. Any change in service requires the reloading of service maps stored in relational data bases; each new variable for service requires another table, essentially another dimension in the relational database. Each variable is implemented at a stop point in the switching fabric. Switches still require complex programming and cost in the millions of dollars.
It is an object of the present invention to provide improved systems and methods for call and call feature setup, administration and processing.
Another object is to provide such methods and apparatus as reduce the overhead required for implementation or modification of call feature processing.
A related object is to provide such methods and apparatus as facilitate implemenation of call features, whether defined by system designers, service providers or end users.
Still another object of the invention is to provide such methods and apparatus as are facilitate implementation of both complex and routine call feature processing.
Yet another object of the invention is to provide such methods and apparatus as can be implemented on a variety of telecommunications platforms.
Yet still another object of the invention is to provide such methods and apparatus as can be implemented at reduced cost and in less time.